Knockout to reveal content from other layers

Create a knockout

Knockout
options let you specify which layers “punch through” to reveal content from
other layers. For example, you can use a text layer to knock out
a color adjustment layer and reveal a portion of the image using
the original colors.

As you plan your knockout effect, you
need to decide which layer will create the shape of the knockout,
which layers will be punched through, and which layer will be revealed.
If you want to reveal a layer other than the Background,
you can place the layers you want to use in a group or
clipping mask.

Farm logo with shallow knockout to Background layer

Do
one of the following in the Layers panel:

To reveal the background, position the layer that will create the knockout above the layers that will be punched through, and make sure the bottom layer in the image is a Background layer. (Choose Layer > New > Background From Layer to convert a regular layer into a Background layer.)

To reveal a layer above the background, place the layers you want to punch through in a group. The top layer in the group will punch through the grouped layers to the next layer below the group.